 Competition Group: First, we put scFv-eGFP fused protein and Antigen-Mcherry 
fused protein together giving them a short period of time to bind with each other. 
Then we put the origin p185her2/neu ECD (with no fluorescent protein fused with it) 
into the environment. The Antigen-Mcherry fused protein is expected to be 
“outcompeted” by the p185her2/neu ECD and thus be “kicked away” from the scFv-
eGFP fused protein. There will be 9 Competition Groups and each of them uses one 
of the 9 different Antigen-Mcherry fused proteins (9 different antigens: the origin 
p185her2/neu ECD and its 8 mutants). The FRET efficiencies in these groups are called 
 Eco and Ec(1-8). 